The present invention relates generally to the field of electrical cords. Specifically, it relates to electrical cords that lock to prevent disengagement, and do not catch on obstacles.
Use of the common extension cord is nearly universal. Extension cords come in all various lengths, colors and of varying size. Extension cords are used in many applications, from plugging in lamps to running power tools, and in all settings from household use to heavy construction.
In everyday use, it is common for extension cords to become separated from the wall outlet into which they are plugged, or become separated from the power cord of the device being used. When this happens, the user must plug the extension cord or device back in before continuing. In situations in which the cord pulls from a wall plug a distance from the area in which the user is working, the re-plugging of the cord can be an inconvenience. In construction situations especially, such an unplugging can be even more of an inconvenience. For example, construction work often involves working on a ladder, on a roof, or in an enclosed space, at some distance from the point at which the electrical cord is connected to power, or the tool is connected to an extension cord. When an electrical cord comes unplugged in such a situation, the user may have to climb down a ladder, off of a scaffold, or actually exit a structure in order to reconnect the cord. All of this results in lost time, as well as inconvenience.
In certain situations, re-plugging an extension cord in a construction setting is more than inconvenient. When removing asbestos, the person doing the removal, in order to leave the enclosure in which the removal is being performed, must shower out, that is take the time to completely remove any asbestos fibers that may be on his or her person, before leaving the enclosure. If an extension cord comes unplugged while working with power tools within an asbestos enclosure, considerable time will be lost in showering out simply to re-connect the cord. Further, occupational safety standards require ground fault circuit interrupters in asbestos removal sites. Typical add-on ground fault circuit interrupters are bulky and have a tendency to catch on corners and objects, leading to the unplugging of cards.
To combat the problem of extension cords pulling out of wall sockets and extension cords pulling loose from power cords of devices, users have come up with several ways to stop such occurrences. For example, it is fairly common for a user to tie a simple knot where the extension cord and another cord meet thereby isolating the joint between the two cords and preventing the cords from separating. Also, specially designed enclosures have been used which isolate the joint between two cords by placing the end pieces into a box or similar structure to prevent the pulling out of the cords.
Such attempts at maintaining the integrity of the connection have been successful in a limited way. Tieing a knot in an extension cord may have a tendency to, over time, weaken the cord to a point where the wires of the cord are broken and the cord becomes unusable. Further, the tieing of knots or the use of bulky enclosures creates the further problem of the cord catching on various objects, such as ladder rungs, door frames, wall corners, and the like. Even typical cords have sharp edges that catch on corners and objects. When this happens a severe jolt can be given to the device being used, the cord, or both. The cord, tool or device being used may suffer damage and further time may be lost in either replacing the cord or the tool.
Attempts have also been made at fashioning wall sockets and specialized plugs that will allow the locking of a cord into a wall outlet. However, these types of devices have generally required a number of moving parts and are generally incompatible with existing cords. Either a specialized cord is required or the modified outlet cannot accept normally configured cords.
Given the problems with the prior art, namely that the methods and devices used to hold cords together are bulky, potentially damaging to the cord, and easily catch on obstacles, causing potential trauma to the cord and tool used, there exists a need for a non-catching, locking electrical cord.